Coating and developing apparatus and pattern forming method

ABSTRACT

A coating and developing apparatus has an interface section equipped with a temperature adjuster (a cooling unit). A temperature-raised substrate due to exposure on periphery of the substrate outside a circuit-forming area thereon is adjusted to a predetermined temperature by the temperature adjuster and then transferred to an exposing apparatus. The temperature adjustments before exposure provide almost the same temperature over many substrates to be transferred to the exposing apparatus for less thermal effects to exposing processing, thus achieving high yields. The interface section is further provided with first and second transfer mechanisms, the first serving to transfer substrates between the processor and the exposing apparatus and the second serving to transfer substrates to each unit of a shelf section, for high transfer performance, thus achieving high throughput.

FIELD OF THE INVENTION

The present invention relates to a coating and developing apparatus forforming resist films on substrates such as semiconductor wafers, LCDsubstrates (glass substrates used for liquid crystal displays) anddeveloping the substrates after exposure to form a desired patternthereon and also a pattern forming method for forming a desired patternwith this apparatus.

BACKGROUND OF THE INVENTION

Photolithographic techniques in process for manufacturing semiconductordevices and LCDs, etc., include the following steps.

Firstly, a substrate such as a semiconductor wafer (called waferhereinafter) is applied a resist solution thereon to be coated with aresist film. The resist film is exposed to a desired pattern through aphotomask. A resist film with the desired pattern is then formed throughdeveloping processing. A series of these processing are carried out in asystem equipped with a coating and developing apparatus and an exposingapparatus connected to each other.

FIG. 1 is a plan view showing such a known system. A cassette Ccontaining substrates, for example 25 semiconductor wafers W, istransferred into a carrier stage 1 on a carrier station A1. Connected tothe carrier station A1 is a processing block A2. Connected further tothe processing block A2 is an exposing apparatus A4 via an interfaceblock A3.

Each wafer W contained in the carrier C on the carrier stage 1 is pickedup by a loading arm 11 and transferred to a coating unit 13 via atransfer mechanism of a shelf unit 12A, for resist coating. The wafer Wis then transferred to a cooling section 15 of a shelf unit 12B by awafer transfer mechanism 14, as shown in FIG. 2. The wafer W is receivedby a transfer arm 16 of the interface block A3 and transferred toperipheral exposing apparatus 17 of the interface block A3.

The peripheral exposing apparatus 17 exposes the periphery of the waferW to remove a resist on the periphery, which may otherwise causegeneration of particles in the later processing. The wafer W that hasbeen subjected to peripheral exposure is, for example, once transferredto a buffer cassette 18 of the block A3. The wafer W is thentransferred, via the transfer arm 16, onto a loading stage (not shown)on the exposing apparatus A4 for exposure.

The exposed wafer W is transferred by the transfer arm 16 of theinterface block A3 to the processing block A2 via a loading section 19of the shelf unit 12B of the processing block A2. After developed by adeveloping unit (not shown) provided under coating unit 13, the wafer Wis returned to the cassette C by the wafer transfer mechanism 14 and theloading arm 11.

The transfer arm 16 provided on the interface block A3 can moveforward/backward and upward/downward, and rotate about a vertical axis,and further move in one horizontal-axis direction along a horizontalrail.

Peripheral exposure for the wafers W formed on which is a very narrowresist pattern in accordance with miniaturized semiconductors will causetemperature increase of, for example, 1° C. for the wafers W due toultraviolet radiation. Moreover, loading the wafers W into the buffercassette 18 before transfer to the exposing apparatus A4 will causegeneration of heat in the tight cassette 18, the wafer temperature beingthus hardly decreased because heat is hardly released.

It is a requirement for exposing processing that the wafers W are at acertain temperature set at the exposing apparatus A4. Temperature changeoutside the set temperature could cause wafer expansion or contractionwith low accuracy of alignment in exposure, thus resulting in lowpattern-size fidelity.

Recent trends in semiconductor fabrication are higher processing speedfor the exposing apparatus A4 and shorter waiting time for the wafers Win the buffer cassette 18. These requirements do not allow sufficientdecrease in wafer temperature raised due to peripheral exposure whilethe wafers W are waiting for exposing processing. This often causestemperature increase for the wafers W while being transferred to theexposing apparatus A4, which results in low yields due to effects ofheat generated during exposure and thus causing low productivity.

SUMMARY OF THE INVENTION

A purpose of the present invention is to provide a coating anddeveloping apparatus and a pattern forming method for providing stablesubstrate temperature in exposure processing, thus achieving highyields, high transfer performance and high throughput.

The present invention provides a coating and developing apparatuscomprising: a carrier table on which at least one carrier containing aplurality of substrates is set; a processor for applying a resist oneach substrate taken out from the carrier set on the carrier table anddeveloping the substrate after being subjected to exposing processing;and an interface section for transferring the resist-coated substratebetween the processor and an exposing apparatus for applying theexposing processing to the resist-coated substrate, the interfacesection including; at least one temperature adjuster for adjusting atemperature of the substrate to an appropriate temperature for theexposing processing before the substrate is transferred to the exposingapparatus; and a transfer mechanism for transferring the substrate amongthe processor, the temperature adjuster and the exposing apparatus.

Moreover, the present invention provides a coating and developingapparatus comprising: a carrier table on which at least one carriercontaining a plurality of substrates is set; a processor for applying aresist on each substrate taken out from the carrier set on the carriertable and developing the substrate after being subjected to exposingprocessing; and an interface section for transferring the resist-coatedsubstrate between the processor and an exposing apparatus for applyingthe exposing processing to the resist-coated substrate, the interfacesection including; a shelf section having a plurality of processingunits for containing or processing the substrate; a first transfermechanism for transferring the substrate between the processor and theexposing apparatus; and a second transfer mechanism for receiving thesubstrate transferred from the processor by the first transfer mechanismand transferring the received substrate to any of the units of the shelfsection.

Moreover, the present invention provides a method of forming a patterncomprising the steps of: applying a resist on a surface of a substrate;adjusting a temperature of the resist-coated substrate to an appropriatetemperature for exposing processing; exposing the temperature-adjustedsubstrate; and developing the exposed substrate to form a resist patternon the substrate surface.

Furthermore, the present invention provides a method of forming apattern comprising the steps of: applying a resist on a surface of asubstrate; exposing periphery of the resist-coated substrate outside acircuit-forming area thereon; adjusting a temperature of theperipheral-exposed substrate to an appropriate temperature for exposingprocessing; exposing the temperature-adjusted substrate; and developingthe exposed substrate to form a resist pattern on the substrate surface.

Moreover, the present invention provides a method of forming a patterncomprising the steps of: applying a resist on a surface of a substrate;adjusting a temperature of the resist-coated substrate to an appropriatetemperature for exposing processing; exposing the temperature-adjustedsubstrate; exposing periphery of the exposed substrate outside acircuit-forming area thereon; and developing the peripheral-exposedsubstrate to form a resist pattern on the substrate surface.

Furthermore, the present invention provides a method of forming a resistpattern on a surface of a substrate, for a coating and developingapparatus having a processor for applying a resist on a substrate anddeveloping the substrate after being subjected to exposing processingand an interface section for transferring the substrate between theprocessor and an exposing apparatus for applying the exposing processingto the substrate, the method comprising the steps of: applying a resiston a surface of a substrate by the processor; transferring theresist-coated substrate from the processor to the interface section by afirst transfer mechanism and adjusting a temperature of theresist-coated substrate to an appropriate temperature for the exposingprocessing in the interface section before the resist-coated substrateis transferred to the exposing apparatus; transferring thetemperature-adjusted substrate from the interface section to theexposing apparatus by the first transfer mechanism and exposing thetemperature-adjusted substrate by the exposing apparatus; andtransferring the exposed substrate from the exposing apparatus to theprocessor via the interface section by the first transfer mechanism anddeveloping the exposed substrate by the processor to form a resistpattern on the substrate surface.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view showing a known coating and developing apparatus;

FIG. 2 is a sectional view showing an interface section of the knowncoating and developing apparatus;

FIG. 3 is a plan view showing an entire structure of an embodiment of acoating and developing apparatus according to the present invention;

FIG. 4 is a perspective view showing an appearance of an embodiment of acoating and developing apparatus according to the present invention;

FIG. 5 is a vertical side view showing the main section of a coatingunit;

FIG. 6 is a vertical side view showing the main section of a shelf unit;

FIG. 7 is a sectional view showing an interface section viewed from thecarrier station side;

FIG. 8 is a perspective view showing an example of a shelf unit providedin an interface section;

FIG. 9 is a side view showing the self unit viewed from the sub-transferarm side;

FIG. 10 is a sectional view showing a cooling unit provided in aninterface section;

FIG. 11 is a plan view showing a main-transfer arm and a sub-transferarm provided in an interface section;

FIG. 12 is a sectional view showing a peripheral exposing apparatusprovided in an interface section; and

FIG. 13 is a perspective view showing an appearance of an interfacesection.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of a coating and developing apparatus according tothe present invention will be disclosed with reference to the attacheddrawings.

FIG. 3 is a plan view showing an entire structure of a resist-patternforming system having a coating and developing apparatus 100 and anexposing apparatus 200 connected to each other. FIG. 4 illustrates anappearance of the resist-pattern forming system shown in FIG. 3.

In the drawings, a carrier station 21 is used for receiving andtransferring a carrier C containing, for example, 25 semiconductorwafers (called wafers) W as substrates. The carrier station 21 isequipped with a carrier table 22 on which the carrier C will be set anda loading mechanism 23. The loading mechanism 23 takes out each wafer W(substrate) from the carrier C and transfers it to a processing sectionS1 provided behind the carrier station 21 viewed from the carrier table22 side.

A main-transfer mechanism 24 is provided in the middle section of theprocessing section S1. When viewed from the carrier station 21 side, twocoating units 3A and two developing units 3B are arranged on the rightside, and shelf units U1, U2 and U3 are arranged on the left, the frontand the right side, mechanism 24. Each of shelf units U1, U2 and U3 isprovided with a stack of several heating and cooling units. The coatingunits 3A are set under the developing units 3B.

The coating unit 3A and the developing unit 3B are disclosed in detail.

An example of the coating unit 3A is disclosed with reference to FIG. 5.A spin chuck 31 is a substrate holder for holding a wafer W horizontallyby vacuum suction. The spin chuck 31 is rotated about a vertical axisand elevated by a driver 32 having a motor and an elevating mechanism(both not shown).

Provided around the spin chuck 31 is a liquid cup 33 that covers theside section of both wafer W and spin chuck 31 and is formed withconcavity on the entire lower periphery. Connected to the bottom of thecup 33 are an exhaust pipe 34 and a drain pipe 35. Provided over the cup33 is a resist supply nozzle 36. The nozzle 36 is movable from theoutside of the cup 33 to the center over a wafer W and vise versa.

In the coating unit 3A, a wafer W is transferred to the spin chuck 31 bythe main-transfer mechanism 24. A resist solution is sprayed onto thecenter of the wafer W while the spin chuck 33 is rotating at apredetermined speed. The resist solution is spread over the wafer W inthe radius direction due to the centrifugal force, thus a resist-coatingfilm being formed on the wafer surface. The resist solution spit outsidethe wafer W is flown into the cup 33.

The developing unit 3B has almost the same structure as the coating unit3A. The unit 3B is, however, equipped with a supply nozzle having manypores aligned for example in the diameter direction of a wafer W. Adeveloping solution is supplied onto the center of the wafer W from thesupply nozzle while the spin chuck 33 is rotating at a predeterminedspeed so that the wafer W is covered with the developing solution.

Although the shelf units U2 and U3 only are illustrated in FIG. 6, theshelf units U1, U2 and U3 are equipped with a stack of heating units 25,cooling units 26, wafer-loading units 27 a and 27 b, a hydrophobicprocessing unit 28 and an alignment unit 29, etc.

In the heating unit 25, a wafer W is set, for a predetermined period, ona plate heated to a predetermined temperature so that it is heated tothe predetermined temperature. In the cooling unit 26, a wafer W is set,for a predetermined period, on a plate cooled to a predeterminedtemperature so that it is cooled to the predetermined temperature.

The loading units 27 a and 27 b are equipped with a loading table havingfor example elevatable pins. The unit 27 a receives and transfers awafer W between the loading mechanism 23 of the carrier station 21 andthe main-transfer mechanism 24 of the processing section S1. The unit 27b receives and transfers a wafer W between the main-transfer mechanism24 of the processing section S1 and a main-transfer arm 4 of aninterface section S2 which will be described later.

The main-transfer mechanism 24 can move upward/downward andforward/backward, and rotate about a vertical axis, for transferringwafers W among the shelf units U1 U2 and U3, the coating units 3A anddeveloping units 3B. The loading mechanism 23 and the main-transfermechanism 24 are not shown in FIG. 4 for simplicity.

The processing section S1 is connected to an exposing apparatus 200 viathe interface section S2. As shown in FIGS. 3 and 7, the sectional viewsfrom the exposing apparatus 200 side, the interface section S2 isequipped with a shelf unit U4 almost at the center, which has the stackof a peripheral exposing unit and a buffer cassette unit, etc. Alsoprovided in the interface section S2, behind the carrier station 21viewed from the station 21, are the main-transfer arm 4 (a firsttransfer mechanism) at the right side and a sub-transfer arm 5 (a secondtransfer mechanism) at the left side, both aligned almost on a straightline.

In the shelf unit U4, as shown in FIG. 8 (the perspective view) and FIG.9 (the side view looked at from the sub-transfer arm 5 side), twotemperature-adjusting units 61, an output loading unit 62, an inputloading unit 64, two buffer cassettes 63, a waiting stage 60, anotherinput loading unit 64 and a peripheral exposing apparatus 65 are stackedin this order from the bottom. The output loading unit 62 and the inputloading unit 64 over the temperature-adjusting units 61 are aligned whenviewed from the sub-transfer arm 5 side. The buffer cassettes 63, thewaiting stage 60 and the other input loading unit 64 are also alignedwhen viewed from the sub-transfer arm 5 side.

The main-transfer arm 4 transfers a wafer W between the cooling units 26and the loading unit 27 b, etc., in the shelf unit U3 of the processingsection S1. The main-transfer arm 4 further transfers a wafer W amongthe output loading unit 62, the input loading unit 64 and thetemperature-adjusting units 61 in the shelf unit U4 of the interfacesection S2 and also the loading stage 210 of the exposing apparatus 200.For such transfer, an arm 41 is provided as movable forward and backwardalong a base 42. The base 42 itself is rotatable about a vertical axisand movable upward/downward along a vertical guide rail 43,forward/backward along a first horizontal guide rail 44 in a firsthorizontal-axis direction towards the shelf unit U4 (or movable in alateral direction behind the carrier station 21 viewed from the station21), and also slidable along a second horizontal guide rail 45 in asecond horizontal-axis direction orthogonal to the first horizontal-axisdirection (or movable in a longitudinal direction behind the carrierstation 21 viewed from the station 21).

The sub-transfer arm 5 transfers a wafer W among the units in theinterface section S2. For such transfer, an arm 51 is provided asmovable forward and backward along a base 52. The base 52 itself isrotatable about a vertical axis and movable upward/downward along avertical guide rail 53.

The temperature-adjusting unit 61 has a plate made of aluminum orceramics, etc., for adjusting the temperature of a wafer W set thereonto a set temperature, provided in a housing 54 having an inlet 54 a andan outlet 54 b. More precisely, the temperature-adjusting unit 61 isequipped with a temperature-adjusting plate 55 and an elevating-pinmechanism 56 for setting a wafer W on the plate 55. Provided in thetemperature-adjusting plate 55 are, for example, a thermo-module, acooling mechanism with cooling pipes and a heating mechanism with aheating resistor.

Both output and input loading units 62 and 64 receive and transfer awafer W between the main-transfer arm 4 and the sub-transfer arm 5, botharms being provided at reachable locations. As shown in FIG. 8, thelower output and input loading units 62 and 64 are aligned on the secondtemperature-adjusting unit 61 from the bottom. Moreover, as shown inFIG. 11, the sub-transfer arm 5 is situated at a position facing almostthe center of the output and input loading units 62 and 64. The upperinput loading unit 64 and the waiting stage 60 are aligned on the twobuffer cassettes 63. The sub-transfer arm 5 is also situated at aposition facing almost the center of the waiting stage 60 and the upperinput loading unit 64.

Each temperature-adjusting unit 61 has a plurality of, for example,three protrusions formed thereon. Each buffer cassette 63 also has aplurality of, for example, three protrusions formed thereon. Theseprotrusions are formed at positions where they are not interfere withthe arms 41 and 51 of the main- and sub-transfer arms 4 and 5,respectively, when the arms 4 and 5 move forward to the respectivepositions for receiving and transferring a wafer W.

A wafer W is temporarily loaded onto the waiting stage 60 from thesub-transfer arm 5 at a sudden power-off like a power outage while thewafer W is set on the arm 5, for a wafer-recovery operation by the arm5. For, example, the sub-transfer arm 5 temporarily loads the wafer Wonto the waiting stage 60 and reaches other units to recover wafers W.The waiting stage 60 thus has the same structure as the loading units 62and 64.

Each buffer cassette 63 has a container 66 for containing the stack of apredetermined number of wafers W. The buffer cassettes 63 receive andtransfer a wafer W from and to the sub-transfer arm 5. Each buffercassette 63 thus has an opening for the container 66 towards thesub-transfer arm 5 so that the arm 5 can reach the wafers W contained inthe container 66. Racks are formed in the container 66 vertically with apredetermined gap therebetween for holding edges of the wafers W so thatthey are arranged vertically.

It is the requirements for the three loading units that two are used asinput loading units to the interface section S2, and the remaining oneis used as an output loading unit. For example, the two units providedon the temperature-adjusting units may be used as the input loadingunits and the unit provided on the buffer cassettes 63 may be used asthe output loading unit. Different from this arrangement, two inputloading units may be provided on the buffer cassettes 63 and one outputloading unit and the waiting stage 60 may be provided on thetemperature-adjusting units 61. The waiting stage 60 may not alwaysnecessary.

The peripheral exposing apparatus 65 performs exposure on the peripheryof each wafer W to remove the resist applied on the periphery outside acircuit-forming area. As illustrated in FIG. 12, the peripheral exposingapparatus 65 is equipped, in a housing 71 having an inlet/outlet 71 a,with a table 72 on which a wafer W is set, a driving mechanism 73 forrotating and moving the table 72 in X- and Y-directions, an exposingunit 74 set so as to face the periphery of the wafer W, and line sensors75 for detecting the periphery of the wafer W, provided over and underthe wafer W so that an area of the wafer W to be detected passes throughbetween the sensors.

In this embodiment, the main-transfer arm 4 can reach the input loadingunit 64, the output loading unit 62 and the temperature-adjusting unit61. The sub-transfer arm 5 can reach the input loading units 64, theoutput loading unit 62, the temperature-adjusting units 61, the buffercassettes 63, the peripheral exposing apparatus 65 and the waiting stage60. Not only this embodiment, it is preferable that the main-transferarm 4 also can reach the waiting stage 60 and/or the sub-transfer arm 5only can reach the temperature-adjusting units 61.

The interface section S2 is an airtight frame, as shown in FIG. 13, withexterior frame walls on the right and left and partitions 81 against theprocessing section S1 and the exposing apparatus 200. Provided on aceiling 82 is a clean-air filter unit F. As shown in FIG. 7, air insidethe interface section S2 is exhausted to a factory exhausting system(not shown) while a portion of the air is sent to a filtering apparatus83 for removing impurities. Air purified by the filtering unit 83 isthen sent to the filter unit F and flown down into the interface sectionS2 through air vents 84 formed on the ceiling 82. This down-flow airprevents temperature increase inside the interface section S2.

The filter unit F is equipped with a filtering section having a filterfor air purification and a chemical filter 85 containing acid forremoving alkalis such as ammonia and amine and an intake fan 86, etc.

The filtering apparatus 83 is equipped with an impurity remover forremoving impurities from air and an adjuster for adjusting air atspecific temperature and humidity and emitting the adjusted air.

A temperature- and humidity-adjusted air is flown into the interfacesection S2 in this embodiment. Not only that, the outside air may betaken into the filter unit F and then flown down into the interfacesection S2.

The interface section S2 is further provided with an inlet/outlet 87 asshown in FIG. 13 for receiving and transferring a wafer W from and tothe shelf unit U3 of the processing section S2 and the loading stage 210of the exposing apparatus 200. The inlet/outlet 87 at the exposingapparatus 200 side is not shown for simplicity.

Provided over the main-transfer arm 4 in the interface section S2 is anelectrical unit E1 covered by a partition wall 88 as shown in FIG. 7.Air from the filter unit F is also passed through the partition wall 88and flown into the interface section S2. Provided over the sub-transferarm 5 is a lamp unit L covered by a partition wall 89.

A film-thickness measuring instrument 9 is set on another electricalunit E2 on the ceiling 82 and in the vicinity of the filter unit F.

The electrical units E1 and E2 include electrical facility such as apower supply for the driving mechanisms of the main-transfer arm 4, thesub-transfer arm 5, the temperature-adjusting unit 61 and peripheralexposing apparatus 65, etc, a controller for power control and a powerboard for power supply.

The lamp unit L includes a lamp, a condensing mirror and a controllerfor controlling these lamp and mirror. The film-thickness measuringinstrument 9 is a light-interference film-thickness measuring instrumentincluding, for example, a microscope, a spectrogragh and a dataprocessor. A light beam emit from a light source is radiated onto awafer W through an objective lens. The light beam reflected from thewafer W is incident to the spectrogragh. The incident refection spectrumis analyzed by a computer for film-thickness measurement.

In this embodiment of a coating and developing apparatus according tothe present invention, a carrier C is always transferred onto thecarrier table 22 from the outside of the apparatus, and the wafers W aretaken out from the carrier C by the loading mechanism 23 one by one.

Each wafer W is transferred from the loading mechanism 23 to themain-transfer mechanism 24 via the loading unit 27 a of the shelf unitU2, and further to the shelf unit U2 (U1 or U3) for hydrophobic andcooling processing, etc.

The wafer W is then sprayed with a resist solution and heated forevaporating the resist solution. The solution-evaporated wafer is cooledby the cooling unit 26 of the shelf unit U3. The cooled wafer W istransferred by the main-transfer arm 4 of the interface section S2 tothe loading unit 64 in the interface section S2.

The wafer W in the loading unit 64 is transferred by the sub-transferarm 5 to the peripheral exposing apparatus 65. After peripheralexposure, the wafer W is transferred by the sub-transfer arm 5 to thebuffer cassette 63. The wafer W is then transferred by the sub-transferarm 5 to the temperature-adjusting unit 61 and subjected to temperatureadjustments, for example, cooled to a set temperature suitable forexposing processing at the exposing apparatus 200.

The wafer W in the temperature-adjusting unit 61 is taken out by themain-transfer arm 4 and transferred to the loading stage 210 of theexposing apparatus 200.

The wafer W for which exposing processing has been completed in theexposing apparatus 200 is returned to the processing section S1 alongthe route of the loading stage 210 of the exposing apparatus 200→themain-transfer arm 4 of the interface section S2→the loading unit 27 b ofthe shelf unit U3.

The wafer W is further transferred by the main-transfer mechanism 24 tothe developing unit 3B for developing processing. In detail, the wafer Wis heated and cooled before developing processing.

The wafer W for which developing processing has been completed istransferred to the loading mechanism 23 along the reverse route to theroute described above and returned to the carrier C that has been set onthe carrier table 22.

This embodiment of a coating and developing apparatus is provided withthe temperature-adjusting units 61 in the interface section S2, foradjusting the temperature of each wafer W to a temperature suitable forexposing processing before transfer to the exposing apparatus 200 evenwhen the wafer temperature is increased due to peripheral exposure.

This temperature adjustment provides almost constant temperature to thewafers W for stable exposing processing with less effects of heat, thusachieving high yields for exposing processing and high productivity.

Moreover, in this embodiment, the main-transfer arm 4 performs wafertransfer between the processing section S1 and the interface section S2,and between the interface section S2 and the exposing apparatus S4whereas the sub-transfer arm 5 performs wafer transfer among the unitsin the shelf unit U4 in the interface section S2.

In other words, the two transfer arms perform wafer transfer separatelyin the interface section S2. This two-arm wafer-transferring processingdecreases the number of processing for each arm for enhancedtransfer-arm performance and also high throughput even when theperipheral exposing apparatus 65 and the temperature-adjusting unit 61are provided in the interface section S2.

In detail, as shown in FIGS. 1 and 2, in the known apparatus, onetransfer arm 16 performs wafer transfer along the route of the coolingunit in the processing section→the peripheral exposing apparatus of theinterface section→the buffer cassette→the loading stage of the exposingapparatus in the processing block A2 that corresponds to the interfacesection S2 in the present invention.

Contrary to this, in the present invention, the main-transfer arm 4performs wafer transfer from the cooling unit 26 of the processingsection S1 to the loading unit 64 of the interface section S2. Afterthis main-arm transfer, the sub-transfer arm 5 performs wafer transferfrom the peripheral exposing apparatus 65 of the interface section S2 tothe buffer cassette 63 and further to the temperature-adjusting unit 61.And then, the main-transfer arm 4 transfers each wafer W to the loadingstage 210 of the exposing apparatus 200.

In other words, the main-transfer arm 4 serves to transfer wafers W insections or units that could suffer a big temperature change whereas thesub-transfer arm 5 serves to transfer them W in sections or units thatwill have almost constant temperature.

The wafer-transfer processing in this invention, requires more number oftransferring steps than the known system. The operating speed for thesub-transfer arm 5 is, however, higher than the main-transfer arm 4 andthose of the known system because the number of driving shafts for thesub-transfer arm 5 is smaller, by one, than the main-transfer arm 4 andthose of the known system. This high operating speed and division ofwafer transfer for the main- and sub-transfer arms in which the numberof transferring steps is different between the two arms offer enhancedtransfer-arm performance and high throughput.

Moreover, in the foregoing embodiment, a temperature- andhumidity-adjusted air is flown down into the interface section S2 forless thermal effects to the peripheral exposing apparatus 65 and thetemperature-adjusting units 61 situated inside the interface section S2,thus a constant temperature is given inside the section S2. This airdown-flow mechanism prevents temperature change from occurring on awafer W before being transferred to the exposing apparatus 200 and alsoa wafer W after exposed but before being transferred to the processingsection S1, which may otherwise occur if the temperature inside theinterface section S2 fluctuates, thus thermal effects to the laterprocessing being reduced.

Air from the filter unit F is also flown down into the partition wall 88that covers the electrical unit E1 in this embodiment, for protectingpartition wall 88 and also the other spaces inside the interface sectionS2 from temperature increase, thus achieving temperature stabilityinside the section S2.

Not only providing a temperature- and humidity-adjusted air, the outsideair may be flown down into the interface section S2 via the filter unitF for temperature stability inside the section S2 because of aircirculation.

Furthermore, the main-transfer arm 4 and the sub-transfer arm 5 arealigned almost on a straight line so that they face each other with theshelf unit U4 interposed therebetween for the peripheral exposingapparatus 65 and the temperature-adjusting unit 61 etc situated in theinterface section S2. This arrangement ensures the spaces for theseveral apparatus and units in the lengthwise direction of the coatingand developing apparatus 100 (X-direction almost orthogonal to thedirection in which several carriers C are aligned on the carrier station21 in FIG. 3), for less increase in footprints.

Disclosed next are modifications to wafer transfer for the interfacesection S2 in the coating and developing apparatus disclosed above.

In detail, a wafer W received by the main-transfer arm 4 from thecooling unit 26 in the shelf unit U3 of the processing section S1 may betransferred along the route of the input loading unit 64→thesub-transfer arm 5→the peripheral exposing apparatus 65→the sub-transferarm 5→the buffer cassette 63→the sub-transfer arm 5→thetemperature-adjusting unit 61→the main-transfer arm 443 the exposingapparatus 200→the main-transfer arm 4→the input loading unit 64→thesub-transfer arm 5→the buffer cassette 63→the sub-transfer arm 5→theoutput loading unit 62.

A wafer W received by the main-transfer arm 4 from the cooling unit 26in the shelf unit U3 of the processing section S1 may also betransferred along the route of the input loading unit 64→thesub-transfer arm 5→the buffer cassette 63→the sub-transfer arm 5→thetemperature-adjusting unit 61→the main-transfer arm 4→the exposingapparatus 200→the main-transfer arm 4→the input loading unit 64→thesub-transfer arm 5→the peripheral exposing apparatus 65→the sub-transferarm 5→the output loading unit 62.

Moreover, a wafer W received by the main-transfer arm 4 from the coolingunit 26 in the shelf unit U3 of the processing section S1 may also betransferred along the route of the input loading unit 64→thesub-transfer arm 5→the buffer cassette 63→the sub-transfer arm 5→thetemperature-adjusting unit 61→the main-transfer arm 4→the exposingapparatus 200→the main-transfer arm 4→the input loading unit 64→thesub-transfer arm 5→the buffer cassette 63→the sub-transfer arm 5→theperipheral exposing apparatus 65→the sub-transfer arm 5→the outputloading unit 62.

The main-transfer arm 4 and the sub-transfer arm 5 are preferablycontrolled as disclosed below in the interface section S2 for higherthroughput.

This transfer control solves a problem occurring in wafer transfer fromthe main-transfer arm 4 to the sub-transfer arm 5 via the input loadingunit 64 in that the main-transfer arm 4 cannot start wafer transfer tothe loading unit 64 before the sub-transfer arm 5 takes out a wafer Wthat has already been transferred to the loading unit 64.

In order to avoid such a problem, in wafer transfer from themain-transfer arm 4 to the input loading unit 64, when the sub-transferarm 5 starts to take out a wafer W that has already been transferred tothe loading unit 64, the main-transfer arm 4 simultaneously starts totransfer a next wafer W to the loading unit 64.

This main- and sub-transfer control shortens a waiting time for themain-transfer arm 4 to start wafer transfer, thus achieving higherthroughput.

Wafer transfer from the sub-transfer arm 5 to the main-transfer arm 4can also be performed in a similar way, in wafer transfer from thesub-transfer arm 5 to the output loading unit 62, when the main-transferarm 4 starts to take out a wafer W that has already been transferred tothe loading unit 62, the sub-transfer arm 5 simultaneously starts totransfer a next wafer W to the loading unit 62.

The present invention, not only limited to the foregoing embodiment,includes any arrangements in which at least the temperature-adjustingunit 61 in the interface section S2 adjusts a temperature of a wafer Wtransferred from the processing section S1 to the exposing apparatus 200to a most appropriate temperature for exposing processing. In such anarrangement, peripheral exposure may not always necessary or may beperformed after the exposing processing.

A heater may be provided as the temperature-adjusting unit for heating awafer W to an appropriate temperature when the temperature of the waferW transferred from the processing section 1 to the exposing apparatus200 is lower than the most appropriate temperature for the exposingprocessing. The peripheral exposing apparatus 65 may not be provided inthe interface section S2.

The temperature-adjusting unit 61 may be provided in the interfacesection S2 so that the main-transfer arm 4 can reach the unit 61.

The structure of the shelf unit U4 in the interface section S2 is notlimited to the foregoing arrangement, for example, a heating unit or aCHP (Chilling Hot Plate) unit may be included. The peripheral exposingapparatus 65 may be provided in the processing section S1.

The arrangement of the main-transfer arm 4, the shelf unit U4 and thesub-transfer arm 5 is flexible with the least requirement that themain-transfer arm 4 performs wafer transfer among the processing sectionS1, the shelf unit U4, the exposing apparatus 200 and the loading units62 and 64, and the sub-transfer arm 5 performs wafer transfer to andfrom the shelf unit U4. The best arrangement for the main- andsub-transfer arms 4 and 5 is that the two arms are aligned on a almoststraight line with the shelf unit U4 interposed therebetween, for lessfootprints, as described above. The buffer cassette 63 may have twoopenings facing the main- and sub-transfer arms 4 and 5, respectively.

Substrates processed by the present invention may be LCD substrates.

As disclosed above, a resist-coated substrate is transferred to theexposing apparatus after a temperature of the substrate is adjusted to amost appropriate temperature for exposing processing by thetemperature-adjusting unit provided in the interface section in thepresent invention. The temperature adjustments before exposure providealmost the same temperature over many substrates for a stable exposingprocessing, thus achieving high yields.

Moreover, the present invention is provided with the first and thesecond transfer mechanisms in the interface section, the first servingto transfer substrates between the processing section and the exposingapparatus and the second serving to transfer substrates to each unit ofthe shelf section, thus achieving high throughput even thoughtemperatures of substrates are adjusted before transferring to theexposing apparatus.

What is claimed is:
 1. A coating and developing apparatus comprising: acarrier table on which at least one carrier containing a plurality ofsubstrates is set; a processor for applying a resist on each substratetaken out from the carrier set on the carrier table and developing thesubstrate after being subjected to exposing processing; an interfacesection for transferring the resist-coated substrate between theprocessor and an exposing apparatus for applying the exposing processingto the resist-coated substrate, the interface section having an airtightstructure and located between the processor and the exposing apparatus;at least one temperature adjuster for adjusting a temperature of thesubstrate to an appropriate temperature for the exposing processingbefore the substrate is transferred to the exposing apparatus; and atransfer mechanism for transferring the substrate among the processor,the temperature adjuster and the exposing apparatus, the temperatureadjustor and the transfer mechanism being housed in the airtightstructure.
 2. The coating and developing apparatus according to claim 1,further comprising: a peripheral exposing apparatus for exposing aperiphery of the substrate outside a circuit-forming area thereon toultraviolet radiation, the peripheral exposing apparatus being housed inthe airtight structure, wherein the transfer mechanism transfers thesubstrate among the processor, the temperature adjuster and theperipheral exposing apparatus.
 3. The coating and developing apparatusaccording to claim 2, wherein the interface section includes a pluralityof temperature adjusters stacked under the peripheral exposingapparatus.
 4. The coating and developing apparatus according to claim 1,wherein the temperature adjuster adjusts a temperature of the substrate,of which the periphery outside a circuit-forming area thereon has beenexposed, to the appropriate temperature for the exposing processing. 5.The coating and developing apparatus according to claim 1, wherein theinterface section further includes a clean-air filter unit, air passedthrough the clean-air filter unit being flown down into the interfacesection.
 6. The coating and developing apparatus according to claim 5,wherein the interface section further includes an electrical unithousing electrical facility, the air passed through the clean-air filterunit being also flown down into a space for the electrical unit in theinterface section.
 7. A coating and developing apparatus comprising: acarrier table on which at least one carrier containing a plurality ofsubstrates is set; a processor for applying a resist on each substratetaken out from the carrier set on the carrier table and developing thesubstrate after being subjected to exposing processing; an interfaceSection for transferring the resist-coated substrate between theprocessor and an exposing apparatus for applying the exposing processingto the resist-coated substrate, the interface section having an airtightstructure and located between the processor and the exposing apparatus;a shelf section having a plurality of processing units for containing orprocessing the substrate; a first transfer mechanism for transferringthe substrate between the processor and the exposing apparatus; and asecond transfer mechanism for receiving the substrate transferred fromthe processor by the first transfer mechanism and transferring thereceived substrate to any of the units of the shelf section, the shelfsection and the first and second transfer mechanisms being housed in theairtight structure.
 8. The coating and developing apparatus according toclaim 7, wherein the shelf section of the interface section includes atleast one temperature adjuster for adjusting a temperature of thesubstrate to an appropriate temperature for the exposing processingbefore the substrate is transferred to the exposing apparatus, thesubstrate being transferred to the temperature adjuster by the firstand/or the second transfer mechanisms.
 9. The coating and developingapparatus according to claim 8, wherein the temperature adjuster adjuststhe temperature of the substrate, of which the periphery outside thecircuit-forming area thereon has been exposed, to the appropriatetemperature for the exposing processing.
 10. The coating and developingapparatus according to claim 7, further comprising: a peripheralexposing apparatus, as one of the units, for exposing periphery of thesubstrate outside a circuit-forming area thereon to ultravioletradiation, the peripheral exposing apparatus being housed in theairtight structure, the substrate that has been transferred from theprocessor by the first transfer mechanism being transferred to theperipheral exposing apparatus by the second transfer mechanism.
 11. Thecoating and developing apparatus according to claim 7, wherein theinterface section further includes a loading unit, as one of the units,for loading the substrate between the first and the second transfermechanisms, the substrate being transferred among the processor, theexposing apparatus and the loading unit by the first transfer mechanismand being transferred between the loading unit and any of the units ofthe shelf section by the second transfer mechanism.
 12. The coating anddeveloping apparatus according to claim 7, wherein the processing unitsare stacked in the shelf section.
 13. The coating and developingapparatus according to claim 7, wherein the first and the secondtransfer mechanisms are aligned on an almost straight line, as the firstand the second transfer mechanisms face each other with the shelfsection interposed therebetween, in a direction almost parallel toanother direction in which the carrier is set on the carrier table. 14.The coating and developing apparatus according to claim 7, wherein thefirst transfer mechanism has an arm for transferring the substrate, thatis movable upward, downward, forward and backward and rotatable about avertical axis, and movable in a direction of a horizontal axis.
 15. Thecoating and developing apparatus according to claim 7, wherein thesecond transfer mechanism has an arm for transferring the substrate,that is movable upward, downward, forward and backward and rotatableabout a vertical axis.
 16. The coating and developing apparatusaccording to claim 7, wherein the interface section further includes aclean-air filter unit, air passed through the clean-air filter unitbeing flown down into the interface section.
 17. The coating anddeveloping apparatus according to claim 16, wherein the interfacesection further includes an electrical unit housing electrical facility,the air passed through the clean-air filter unit being also flown downinto a space for the electrical unit in the interface section.
 18. Acoating and developing apparatus comprising: a carrier table on which atleast one carrier containing a plurality of substrates is set; aprocessor for applying a resist on each substrate taken out from thecarrier set on the carrier table and developing the substrate afterbeing subjected to exposing processing; an interface section fortransferring the resist-coated substrate between the processor and anexposing apparatus for applying the exposing processing to theresist-coated substrate, the interface section having an airtightstructure and located between the processor and the exposing apparatus;at least one temperature adjuster for adjusting a temperature of thesubstrate to an appropriate temperature for the exposing processingbefore the substrate is transferred to the exposing apparatus; atransfer mechanism for transferring the substrate among the processor,the temperature adjuster and the exposing apparatus; and a peripheralexposing apparatus for exposing periphery of the substrate outside acircuit-forming area thereon to ultraviolet radiation, the transfermechanism transferring the substrate among the processor, thetemperature adjuster, and the peripheral exposing apparatus, and whereinthe transfer mechanism is housed in the airtight structure.